<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        let arr1=["zhangsan","lisi","wangwu"]
        let resArr=arr1.filter(value=>value.length===3)
        console.log(resArr)
        let resArr1=arr1.find(value=>value.length===3)
        console.log(resArr1)
        console.log(arr1)
        console.log(arr1.map((value,index,arr)=>{
            console.log(value)
            console.log(index)
            console.log(arr)
            return value+"A"
        }))
        arr1.push(567)
        console.log(arr1)
        arr1.unshift(123)
        console.log(arr1)
        arr1.splice(1,2,"a","b")
        console.log(arr1)
    </script>
</body>
</html>